Since then, he has managed to triple his target and is now hoping to get 100,000 potential donors registered in the UK.

The ex-Ironman triathlete and rugby coach will now compete in this year’s Crumball Rally – a 700-mile (1,126.5km) continental drive through France and Italy – in a Ford Focus costing less than £200.

He hopes his Drive To Survive challenge will help encourage more people to sign up to the register, which holds around 2% of the UK population.

Before setting off for the start line, Mr McCleave told the PA news agency that he has been “blown away” by the groundswell of support that accompanied his campaign.

He has raised almost £25,000 for blood cancer charity DKMS, which will allow a further 625 potential donors to be added.

He said: “All I need to do is play my part in getting that register populated as diversely and broadly as possible so that, when someone is in need of a stem cell match, they have it there and then.

Peter McCleave in hospital, June 2018 (DKMS/PA)

“It shouldn’t be patients running around trying to find stem cell matches at all, so my overriding goal is really to right what I feel is an injustice in terms of medical professionals not having access to those stem cells.”

He added: “It’s great to know that, regardless of what happens to me, I’ve done something useful.

“And it’s not about moping or feeling sorry for myself, it’s about trying to help people, which I guess deep down we all want to do, it’s just finding a vehicle in which to do it.”

Every 20 minutes someone in the UK is diagnosed with a type of blood cancer. It is the third most common cause of cancer death in the UK.

Mr McCleave hopes his race will help raise the profile of Blood Cancer Awareness Month and that people will be encouraged to order a home swab kit from DKMS so their details can be added to the register.

None of his family members were a match when tested, and his Portuguese and Macanese heritage means he has a reduced chance of finding a suitable donor.

People from a black, Asian or other minority ethnic (BAME) background currently make up 14% of the registry and only have a 20% chance of finding the best possible stem cell donor match, compared with 69% for those from northern European backgrounds.

Mr McCleave said: “I genuinely have a belief that there is a match out there; I’ve just got to find it. As long as I have that hope, I’ve made peace with the situation, and I love the fact that we’ve managed to potentially save several lives. I mean, who gets the chance to save a life unless you’re a medical professional?”

He added: “I’ve got two boys aged nine and six, and I took for granted that I’d be able to see them grow up, and that right now is in question.”

Starting from Reims in northern France on Friday morning, he will pass through Turin in Italy, and Monte Carlo on the south coast of France before the challenge comes to an end in Nice.

Peter McCleave (left) with co-driver Richard Newman (DKMS/PA)

Caroline Richardson, head of fundraising at DKMS, said: “We’re so excited that Peter will take on this year’s Crumball Rally. He’s such a selfless man, who’s always actively doing as much as possible to raise awareness of blood cancer.

“Peter has already helped DKMS add over 30,000 people to the aligned registry, seven of whom have been confirmed matches for people with blood cancer.

“He really understands the vital importance of raising funds for our lifesaving work so that DKMS can cover the costs of registering more potential life-savers.

“If Peter manages to reach his fundraising target of £25,000, a further 625 people can be added to the register who could provide hope to someone affected by blood cancer and offer them the potential of a second chance at life.”

The cost of registering a single potential donor on the register is £40, and DKMS relies on donations to help cover the cost.